1. Field of the Invention
The present invention relates generally to medical methods and apparatus. More particularly, the present invention relates to methods and systems for controlling the deployment of needles using visual feedback from an ultrasonic or other image.
Current medical treatments of organs and tissues within a patient's body often use a needle or other elongate body for delivery of energy, therapeutic agents or the like. Optionally the methods use ultrasound imaging to observe and identify a treatment target and the position of the needle relative to the treatment target.
Of particular interest to the present invention, a treatment for uterine fibroids has recently been proposed which relies on the transvaginal positioning of a treatment device in the patient's uterus. A radiofrequency or other energy or therapeutic delivery needle is deployed from the device into the fibroid, and energy and/or therapeutic substances are delivered in order to ablate or treat the fibroid. To facilitate locating the fibroids and positioning the needles within the fibroids, the device includes an on-board ultrasonic imaging array with a field of view in a generally lateral direction from an axial shaft. A curved needle is advanced from the shaft and into the field of view so that the needle can be visualized and directed into the tissue and the targeted fibroid. The geometry of the needle deployment is advantageous since it permits the location and treatment of fibroids which are laterally adjacent to the shaft.
While effective and very beneficial for patients, such needle ablation and treatment protocols face several challenges. First, initial deployment of the needle can be difficult, particularly for physicians who have less experience. While the physician can view the tissue and target anatomy in real time on an imaging screen, it can be difficult to precisely predict the path the needle will take and assess its final treatment position. While the needle can certainly be partially or fully retracted and redeployed, it would be advantageous to minimize the number of deployments required before treatment is effected.
A second challenge comes after the needle has been deployed. While the position of the needle can be observed on the ultrasonic or other visual image, the treatment volume resulting from energy or other therapeutic delivery can be difficult to predict. As with initial positioning, experience will help but the need to exercise judgment and conjecture is best reduced.
A third challenge is in assuring that nearby sensitive tissue structures, such as the serosa surrounding the myometrium, are not unintentionally damaged. As with judging the treatment volume, predicting the safety margin of the treatment can be difficult.
For these reasons, it would be desirable to provide improved systems and methods for the deployment of energy delivery and other needles within ultrasonic or other imaging fields of view in energy delivery or other therapeutic protocols. It would be particularly useful to provide the treating physician with information which would assist in initial deployment of a needle in order to improve the likelihood that the needle will be properly positioned relative to a targeted anatomy to be treated. It would also be desirable, once the needle has been deployed, to provide feedback to the physician to assist in accurately predicting a treatment volume. Such information should allow the physician, if necessary, to reposition the needle in order to increase the likelihood of fully treating the anatomy. Furthermore, it would be desirable to provide feedback to the physician allowing the physician to assess a safety margin so that sensitive tissue structures are not damaged. All such feedback other information are preferably provided visually on the ultrasonic or other imaging screen so that the needle position can be quickly predicted, assessed, and treatment initiated. At least some of these objectives will be met by the inventions described hereinafter.
2. Description of the Background Art
U.S. Patent Publication No. 2006/0189972, published on Aug. 24, 2006 and commonly assigned with the present application, describes probes useful for both imaging and treating uterine fibroids, which probes could be used in the systems and methods of the present application. Other commonly assigned applications describing probes useful for treating uterine fibroids in the systems and methods of the present invention include application Ser. No. 11/409,496, filed on Apr. 20, 2006; Ser. No. 11/564,164, filed on Nov. 20, 2006; Ser. No. 11/620,594, filed on Jan. 5, 2007; and copending provisional application No. 60/938,140, filed on May 15, 2007, the full disclosures of which are incorporated herein by reference. Other related, commonly assigned applications are Ser. No. 11/620,569, filed Jan. 5, 2007; and Ser. No. 11/775,452, filed on Jul. 10, 2007. The full disclosures of each of these commonly owned, pending applications are incorporated herein by reference.